Refrigerant compressor and refrigerant cycle device including the same

ABSTRACT

An object is to provide a refrigerant compressor which solves a disadvantage that an oil flows into a refrigerant circuit in the outside of the refrigerant compressor during introduction of the oil and which minimizes an amount of the oil to be introduced and which can secure a sufficient amount of the oil, and a refrigerant cycle device including the refrigerant compressor. A rotary compressor (refrigerant compressor) comprises, in a sealed container, an electromotive element as a driving element, and a rotary compression mechanism part driven by this electromotive element and constituted of first and second rotary compression elements, and discharges a refrigerant compressed by the rotary compression mechanism part from the sealed container, the compressor further comprising an oil reservoir constituted in a bottom part of the sealed container; and a servicing pipe  100  attached to the sealed container to introduce the refrigerant and the oil into the sealed container.

BACKGROUND OF THE INVENTION

The present invention relates to a refrigerant compressor which includes, in a sealed container, a driving element and a compression element driven by the driving element and which discharges a refrigerant compressed by the compression element from the sealed container. The present invention also relates to a refrigerant cycle device including the refrigerant compressor.

Heretofore, in a refrigerant cycle device including this type of refrigerant compressor, the refrigerant compressor, a radiator, a capillary tube (throttle means), an evaporator and the like are successively annularly connected to one another by pipes to constitute a refrigerant circuit. In a refrigerant compressor such as a rotary compressor including, in a sealed container, a driving element and a rotary compression element driven by the driving element, a refrigerant gas is sucked from a suction port of the rotary compression element into a cylinder on the side of a low-pressure chamber. The gas is compressed by an operation of a roller and a vane to form a high-temperature high-pressure refrigerant gas. After the gas is discharged from the cylinder on the side of a high-pressure chamber into the sealed container through a discharge port and a discharge sound absorbing chamber, the gas is discharged from the compressor.

Moreover, an oil reservoir is disposed in a bottom part of the sealed container, and an oil is pumped up from the oil reservoir by an oil pump (oil supply means) attached to one end (lower end) of a rotation shaft, and supplied to sliding portions and the like of the rotary compression element to lubricate and seal the element (see, e.g., Japanese Patent Application Laid-Open No. 2004-27970).

In addition, in a case where the refrigerant and the oil are introduced into the conventional refrigerant compressor, a servicing pipe for introducing the refrigerant and the oil is attached beforehand as one of the pipes which connect devices constituting the refrigerant circuit to one another, and the refrigerant and the oil are introduced while drawing a vacuum in the refrigerant circuit.

However, in a case where the refrigerant and the oil are introduced through the servicing pipe connected to a refrigerant pipe while drawing the vacuum in the refrigerant circuit, the oil enters even a refrigerant circuit in the outside of the refrigerant compressor. Therefore, an amount of the oil actually introduced into the refrigerant compressor is reduced is reduced.

Especially in a small-sized refrigerant compressor having a small amount of the oil to be introduced, a reservoir of the refrigerant compressor, and this causes a problem that a sliding property and a sealing property deteriorate. When the amount of the oil to be introduced is increased to solve such an oil shortage, the amount of the oil in the outside of the refrigerant compressor also increases. Therefore, the refrigerant circuit might adversely be affected.

Especially in a refrigerant cycle device for a low temperature, such as a freezer, since a passage resistance is increased so as to sufficiently reduce the pressure of the refrigerant in the capillary tube, the capillary tube is closed by the oil discharged into the refrigerant circuit, and this causes a trouble in an operation of the device.

SUMMARY OF THE INVENTION

The present invention has been developed to solve the problem of such a conventional technology, and an object thereof is to provide a refrigerant compressor which solves a disadvantage that oil flows out of the refrigerant compressor during introduction of the oil and in which an amount of the oil to be introduced is suppressed as much as possible but a sufficient amount of the oil can be secured. Another object is to provide a refrigerant cycle device including the refrigerant compressor.

A refrigerant compressor of the present invention comprises, in a sealed container, a driving element, and a compression element driven by the driving element, the refrigerant compressor being configured to discharge a refrigerant compressed by the compression element from the sealed container, the refrigerant compressor further comprising an oil reservoir constituted in a bottom part of the sealed container; and a servicing pipe attached to the sealed container to introduce the refrigerant and an oil into the sealed container.

Moreover, in the refrigerant compressor of the present invention, the sealed container of the above invention includes a container main body having a longitudinally long cylindrical shape, and an end cap which closes an upper-end opening of this container main body, the compression element is contained in a lower part of the container main body, the driving element is disposed in an upper part of the container main body, the oil reservoir is constituted in a bottom part of the container main body, and the servicing pipe is attached to the container main body above the driving element.

A refrigerant cycle device of the present invention comprises: a refrigerant circuit constituted by connecting the refrigerant compressor of the above invention, a radiator, throttle means, an evaporator and the like to one another by pipes.

Moreover, the refrigerant cycle device of the present invention is characterized in that in the above invention, a carbon dioxide refrigerant is used as the refrigerant.

According to the refrigerant compressor of the present invention, since the sealed container is provided with the servicing pipe for introducing the refrigerant and the oil into the sealed container, the refrigerant and the oil can directly be introduced from the servicing pipe into the sealed container.

Accordingly, a sufficient amount of the oil can be secured in the refrigerant compressor. Since all the oil can securely be introduced into the sealed container, the amount of the oil to be introduced into the refrigerant compressor can be minimized.

Especially, since the compression element is contained in the lower part of the container main body, the driving element is disposed in the upper part of the container main body, the oil reservoir is constituted in the bottom part of the container main body, and the servicing pipe is attached to the container main body above the driving element, it is possible to easily introduce the refrigerant and the oil from a position which does not interfere with the driving element and the compression element and which is above the oil reservoir.

Moreover, since the refrigerant compressor of the above invention, the radiator, the throttle means and the evaporator are connected to one another by the pipes to constitute the refrigerant circuit, it is possible to solve a disadvantage that the oil flows out of the refrigerant compressor during the introduction of the oil, and it is possible to secure an operation performance of the refrigerant cycle device including the refrigerant compressor.

Especially, in a case where carbon dioxide is used as the refrigerant, it is possible to solve a disadvantage that the introduced oil remains in the throttle means to close the means.

As described above, it is possible to enhance reliability and performance of the refrigerant cycle device including the refrigerant compressor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal side view of a rotary compressor in one embodiment of the present invention; and

FIG. 2 is a refrigerant circuit diagram of a refrigerant cycle device including the rotary compressor of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of a rotary compressor of the present invention will be described hereinafter in detail with reference to the drawings. FIG. 1 shows a longitudinal side view of a rotary compressor 10 as one embodiment of a refrigerant compressor of the present invention. The rotary compressor includes, in a sealed container 12, an electromotive element 14 as a driving element and a rotary compressor mechanism part 18 as a compression element driven by this electromotive element 14.

In FIG. 1, the rotary compressor 10 of the present embodiment is an inner high pressure type rotary compressor in which the rotary compressor mechanism part 18 is constituted of first and second rotary compression elements 32, 34, and a refrigerant compressed by the first rotary compression element 32 is sucked into the second rotary compression element 34 to compress the refrigerant. After the refrigerant is discharged into the sealed container 12, it is discharged from the sealed container 12.

The sealed container 12 is constituted of a container main body 12A having a longitudinally long cylindrical shape, and a substantially bowl-like end cap (lid member) 12B which closes an upper-end opening of this container main body 12A, the rotary compressor mechanism part 18 is contained in a lower part of the container main body 12A, and the electromotive element 14 is disposed in an upper part of the container main body 12A. Moreover, an oil reservoir 80 is constituted in a bottom part of the container main body 12A.

A circular attachment hole 12D is formed in the top of the end cap 12B, and a terminal (wiring line is omitted) 20 for supplying power to the electromotive element 14 is attached to this attachment hole 12D.

The electromotive element 14 is constituted of a stator 22 annularly fixed by welding along an inner peripheral surface of the sealed container 12 in an upper space of the container, and a rotor 24 inserted in the container and disposed at a slight interval from an inner surface of this stator 22. This rotor 24 is fixed to a rotation shaft 16 extending through the center of the container in a vertical direction.

The stator 22 has a laminate member 26 constituted by laminating donut-like electromagnetic steel plates, and a stator coil 28 wound around a tooth part of this laminate member 26 by a series (concentrated winding) system. The rotor 24 is also formed of a laminate member 30 of the electromagnetic steel plates in the same manner as in the stator 22.

The rotary compressor mechanism part 18 is divided by an intermediate partition plate 36 into the second rotary compression element 34 constituting a second stage on the side of the electromotive element 14 in the sealed container 12, and the first rotary compression element 32 constituting a first stage disposed opposite to the electromotive element 14. That is, the second rotary compression element 34 and the first rotary compression element 32 are constituted of: upper and lower cylinders 38 and 40 disposed on and under the intermediate partition plate 36 and constituting the second and first rotary compression elements 34, 32; and rollers 46, 48 fitted into upper and lower eccentric portions 42, 44 formed on the rotation shaft 16 of the electromotive element 14 to rotate eccentrically in the cylinders 38, 40, respectively. The elements are also constituted of: a vane (not shown) which abuts on the rollers 46, 48 to define the cylinders 38, 40 on a low-pressure chamber side and a high-pressure chamber side; a lower support member 56 which closes one (lower) opening of the lower cylinder 40, the lower support member constituting a support member having a bearing 56A of the rotation shaft 16; and an upper support member 54 which closes an upper opening of the upper cylinder 38, the upper support member having a bearing 54A of the rotation shaft 16. It is to be noted that the upper and lower eccentric portions 42, 44 disposed on the rotation shaft 16 have a phase difference of 180 degrees.

The upper support member 54 and the lower support member 56 are provided with: suction passages 58, 60 which communicate with inner parts of the upper and lower cylinders 38, 40 by suction ports 160, 161; a discharge sound absorbing chamber 62 formed by depressing the surface of the upper support member 54 on the side (upper side) opposite to the upper cylinder 38, and closing this depressed concave portion with an upper cover 63; and a discharge sound absorbing chamber 64 formed by depressing the surface of the lower support member 56 on the side (lower side) opposite to the lower cylinder 40, and closing this depressed concave portion with a lower cover 68. That is, the discharge sound absorbing chamber 62 is closed with the upper cover 63, and the discharge sound absorbing chamber 64 is closed with the lower cover 68. In this case, the bearing 54A is raised from the center of the upper support member 54, and the bearing 56A is similarly extended through the center of the lower support member 56.

Moreover, the lower cover 68 is constituted of a donut-like circular steel plate, four peripheral portions of the cover are fixed to the lower support member 56 from below by lower bolts, and the lower cover closes an opening in the undersurface of the discharge sound absorbing chamber 64 which communicates the inner part of the lower cylinder 40 of the first rotary compression element 32 by a discharge port. A distant end of each bolt engages with the upper support member 54.

In the upper cover 63, a communication path (not shown) is formed so that the discharge sound absorbing chamber 62 communicates with the sealed container 12, and the high-temperature high-pressure refrigerant gas compressed by the second rotary compression element 34 is discharged from the communication path into the sealed container 12.

On the other hand, one end (lower end) of the rotation shaft 16 is attached to an oil pump 81 as oil supply means for pumping up the oil pooled in the oil reservoir 80. The oil pumped up by the oil pump is supplied to sliding portions and the like of the rotary compressor mechanism part 18 from an oil hole 88 formed in the center of the rotation shaft 16 in the vertical direction and oil supply holes 82, 84 which communicate with this oil hole 88 and which are formed in a transverse direction (also formed in the upper and lower eccentric portions 42, 44).

Moreover, in the rotary compressor 10 of the present embodiment, it is assumed that carbon dioxide which is a natural refrigerant eco-friendly to global environments is used as the refrigerant. As the oil which is a lubricant, an existing oil is used such as a mineral oil, a polyalkylene glycol (PAG), an alkyl benzene oil, an ether oil or an ester oil.

Furthermore, to the side surface of the container main body 12A of the sealed container 12, sleeves 140, 141, 142 and 143 are fixed by welding in positions corresponding to the suction passages 58, 60 of the upper support member 54 and the lower support member 56 and positions above the discharge sound absorbing chamber 64 and the electromotive element 14, respectively. The sleeve 140 is vertically adjacent to the lower sleeve 141, and the sleeve 142 is disposed substantially along a diagonal line of the sleeve 141.

In the sleeve 140, one end of a refrigerant introducing tube 92 for introducing the refrigerant gas in the upper cylinder 38 is inserted. This end of the refrigerant introducing tube 92 communicates with the suction passage 58. This refrigerant introducing tube 92 passes above the sealed container 12, and reaches the sleeve 142. The other end of the tube is inserted in the sleeve 142 to communicate with the discharge sound absorbing chamber 64.

Moreover, in the sleeve 141, one end of a refrigerant introducing tube 94 for introducing the refrigerant gas to the lower cylinder 40 is inserted. This end of the refrigerant introducing tube 94 communicates with the suction passage 60. In the sleeve 143, a refrigerant discharge tube 96 is inserted, and one end of the refrigerant discharge tube 96 communicates with the inside of the sealed container 12.

On the other hand, a sleeve 144 is fixed by welding to the side surface of the container main body 12A above the electromotive element 14, that is, substantially along a diagonal line of the sleeve 143. In the sleeve 144, a servicing pipe 100 for introducing the refrigerant and the oil into the sealed container 12 as described later is inserted.

As shown in FIG. 2, the rotary compressor 10 described above in detail constitutes a refrigerant cycle device 110 together with a radiator 150, a capillary tube 152 as throttle means, and an evaporator 154. They are successively connected to one another by pipes to constitute a refrigerant circuit of the refrigerant cycle device 110.

Here, in a case where the refrigerant and the oil are introduced into the rotary compressor 10, as shown in FIG. 2, after the rotary compressor 10 is connected to units (the radiator 150, the capillary tube 152 and the evaporator 154) constituting the refrigerant cycle device 110 together with the rotary compressor 10 by the pipes, the refrigerant and the oil are directly introduced into the sealed container 12 from the servicing pipe 100. Moreover, the oil introduced from this servicing pipe 100 flows downwards through gaps of the electromotive element 14 and the rotary compressor mechanism part 18, and is pooled in the oil reservoir 80 formed in the bottom part.

Thereafter, the other end of the servicing pipe 100 which communicates with the outside of the sealed container 12 is pinched, and the opening of the servicing pipe 100 which communicates with the outside of the sealed container 12 is securely closed.

Since a conventional refrigerant compressor is not provided with the servicing pipe for directly introducing the refrigerant and the oil into the sealed container 12, to introduce the refrigerant and the oil into the rotary compressor, the servicing pipe is formed beforehand in one of the pipes connecting the respective units of the refrigerant cycle device to one another. The refrigerant and the oil have to be sucked from the servicing pipe while drawing a vacuum in the refrigerant circuit. However, in this case, since the oil also flows out of the refrigerant compressor, the amount of the operation introduced into the refrigerant compressor is reduced.

Especially, in a small-sized refrigerant compressor having a small amount of the introduced oil, when the oil amount is reduced, a sufficient amount of the oil cannot be secured in the oil reservoir of the refrigerant compressor, it is difficult to supply the oil from the oil pump to the sliding portions and the like of the rotary compressor mechanism part 18, a sliding property and a sealing property deteriorate, and a trouble might be caused in an operation of the rotary compressor. In a case where the amount of the oil to be introduced is increased in order to solve such an oil shortage, the amount of the oil which flows out of the refrigerant compressor also increases. Therefore, the refrigerant circuit might adversely be affected.

Especially, in a refrigerant cycle device for a low temperature, such as a freezer, a capillary tube having a large passage resistance is used so that an evaporation temperature of the refrigerant in the evaporator is lowered. Alternatively, throttle means such as an expansion valve having a throttle amount further enlarged is used. Therefore, the oil which has entered such a refrigerant circuit might remain in the throttle means to close the throttle means.

In addition, in a case where a carbon dioxide refrigerant is used, since the carbon dioxide refrigerant has a low cooling capability as compared with another refrigerant, the throttle amount of the throttle means is further enlarged, the oil easily remains as described above, and the trouble is generated in the operation.

However, when the servicing pipe 100 is formed in the container main body 12A of the sealed container 12 as in the present invention, and the refrigerant and the oil are directly introduced into the sealed container 12 from the servicing pipe 100, it is possible to disadvantage that the oil flows out of the rotary compressor 10 during the introduction of the oil.

Moreover, since all the oil can securely be introduced into the sealed container 12, the amount of the oil to be introduced into the rotary compressor 10 can be minimized.

Furthermore, as in the present embodiment, the servicing pipe 100 is formed in the container main body 12A above the electromotive element 14 so that the pipe does not interfere with the electromotive element 14 and the rotary compressor mechanism part 18. Therefore, the refrigerant and the oil can easily be introduced into the sealed container 12 of the rotary compressor 10.

Next, there will be described an operation of the rotary compressor constituted as described above. When the stator coil 28 of the electromotive element 14 is energized via the terminal 20 and a wiring line (not shown), the electromotive element 14 is started to rotate the rotor 24. With this rotation, the rollers 46, 48 fitted into the upper and lower eccentric portions 42, 44 disposed integrally with the rotation shaft 16 eccentrically rotate in the upper and lower cylinders 38, 40.

Accordingly, a low-pressure refrigerant gas is sucked from the suction port 161 into the lower cylinder 40 on the low-pressure chamber side via the refrigerant introducing tube 94 and the suction passage 60 formed in the lower support member 56, and compressed by an operation of the roller 48 and a vane (not shown) to achieve an intermediate pressure. The gas is discharged into the discharge sound absorbing chamber 64 from the lower cylinder 40 on the high-pressure chamber side through a discharge port (not shown).

The intermediate-pressure refrigerant gas discharged into the discharge sound absorbing chamber 64 passes through the refrigerant introducing tube 92 connected to the discharge sound absorbing chamber 64, and is sucked into the upper cylinder 38 on the low-pressure chamber side from the suction port 160 through the suction passage 58 formed in the upper support member 54.

On the other hand, the intermediate-pressure refrigerant gas sucked into the upper cylinder 38 is compressed in the second stage by an operation of the roller 46 and a vane (not shown) to from a high-temperature high-pressure refrigerant gas. The gas passes through a discharge port (not shown) from the upper cylinder 38 on the high-pressure chamber side, and is discharged into the discharge sound absorbing chamber 62 formed in the upper support member 54.

Moreover, the refrigerant fed into the discharge sound absorbing chamber 62 flows into the sealed container 12 through a communication path (not shown), passes through a gap between the inner peripheral surface of the container and the electromotive element 14, moves to the upper part of the sealed container 12, and is discharged from the rotary compressor 10 through the refrigerant discharge tube 96 connected to the upper part of the sealed container 12. It is to be noted that in a case where the refrigerant fed into the sealed container 12 passes through the gap between the inner peripheral surface of the container and the electromotive element 14, and is discharged from the rotary compressor 10 via the refrigerant discharge tube 96 connected to the upper part of the sealed container 12, the oil mixed with the refrigerant gas can be separated from the refrigerant gas while the gas passes through the gap between the inner peripheral surface of the container and the electromotive element 14. In consequence, it is possible to minimize the amount of the oil discharged from the rotary compressor 10.

As described above in detail, since the refrigerant and the oil can directly be introduced into the sealed container 12 of the rotary compressor 10 by the servicing pipe 100 of the present invention, it is possible to solve a disadvantage that the oil flows out of the rotary compressor 10 to adversely affect the circuit during the introduction of the oil. Since all the oil can securely be introduced into the sealed container 12, the amount of the oil introduced into the rotary compressor 10 can be minimized.

Consequently, it is possible to enhance reliability and performance of the refrigerant cycle device 110 including the rotary compressor 10.

It is to be noted that in the present embodiment, as the refrigerant compressor, there has been described constitution inner high pressure type rotary compressor 10 including the first and second rotary compression elements 32, 34, but the refrigerant compressor rotor of the present invention is not limited to this example. The present invention is applicable to any compressor as long as the compressor includes the driving element and the compression element in the sealed container, and compresses the refrigerant by the compression element. In the embodiment, the vertical compressor has been described in which the rotation shaft is vertically disposed, but needless to say, the present invention is applicable to a horizontal compressor in which the rotation shaft is horizontally disposed.

Moreover, in the embodiment, the servicing pipe 100 is disposed in the container main body 12A above the electromotive element 14, but the position of the servicing pipe 100 of the present invention is not limited to the position in the present embodiment, and the pipe may be disposed in any position as long as the driving element and the compression element are not interfered.

Furthermore, it has been described that carbon dioxide is used as the refrigerant of the rotary compressor, but even if another refrigerant is used, the present invention is effective. 

1. A refrigerant compressor comprising, in a sealed container, a driving element, and a compression element driven by the driving element, the refrigerant compressor being configured to discharge a refrigerant compressed by the compression element from the sealed container, the refrigerant compressor further comprising: an oil reservoir constituted in a bottom part of the sealed container; and a servicing pipe attached to the sealed container to introduce the refrigerant and an oil into the sealed container.
 2. The refrigerant compressor according to claim 1, wherein the sealed container includes a container main body having a longitudinally long cylindrical shape, and an end cap which closes an upper-end opening of the container main body, the compression element is contained in a lower part of the container main body, the driving element is disposed in an upper part of the container main body, the oil reservoir is constituted in a bottom part of the container main body, and the servicing pipe is attached to the container main body above the driving element.
 3. A refrigerant cycle device comprising a refrigerant circuit constituted by connecting the refrigerant compressor according to claim 1, a radiator, throttle means, an evaporator and the like to one another by pipes.
 4. The refrigerant cycle device according to claim 3, wherein carbon dioxide is used as the refrigerant.
 5. A refrigerant cycle device comprising a refrigerant circuit constituted by connecting the refrigerant compressor according to claim 2, a radiator, throttle means, an evaporator and the like to one another by pipes.
 6. The refrigerant cycle device according to claim 5, wherein carbon dioxide is used as the refrigerant. 